Atrial Fibrillation

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• 1874 Alfred Vulpian- ‘Fremissement fibrillaire’• 1876 Carl Nothnagel- ‘Delerium Cordis’

1906- Einthoven- 1st EKG of afib1909- Rothberger,Winterberg& Lewis- correlation between

EKG and pulse

• Atrial Fibrillation-Atrial Fibrillation-

– Absent Absent ‘P’‘P’ waves waves

– Irregular atrial activity- ‘F’ wavesIrregular atrial activity- ‘F’ waves

• Variable- amplitude, duration and Variable- amplitude, duration and morphologymorphology

– Resultant irregular ventricular responseResultant irregular ventricular response– Impostures- atrial flutter and MATImpostures- atrial flutter and MAT

Classification

• First detected- single documented episode

• Recurrent- 2 or more episodes

• Paroxysmal- Spontaneous conversion (usually <7 days)

• Persistent- episodes are sustained (often >7 days)

• Permanent/Chronic- persistent (typically > 1year)

Etiologies

• Valvular Heart Disease- esp. Mitral• Non valvular and Secondary causes

– Cardiomyopathies (IDCM/NIDCM)– Hypertension– Post-CABG/Post operative state– Toxin- Thyrotoxicosis, ETOH– Pulmonary embolus/COPD– Hypoxia/Acidemia– Sinus Node dysfunction– Congenital Heart disease- WPW, ASD

• Lone Atrial Fibrillation– <12% without identifiable cause– Age <60

Conditions Allied with AF

Copyright restrictions may apply.

Go, A. S. et al. JAMA 2001;285:2370-2375.

Prevalence of Diagnosed Atrial Fibrillation Stratified by Age and Sex

In General- <1% of Population < 60 yrs >6-8% of Population >80 yrs

Copyright restrictions may apply.

Go, A. S. et al. JAMA 2001;285:2370-2375.

Projected Number of Adults With Atrial Fibrillation in the United States Between 1995 and 2050

Concerns

• Thromboembolism

• Mortality

• Cardiomyopathy and CHF

• As well as– Known Knowns– Known Unknowns– Unknown Unknowns

Copyright ©2001 American Heart Association

Fuster, V. et al. Circulation 2001;104:2118-2150

Relative risk of stroke and mortality in patients with AF compared with patients without AF

Risk of CV ~5% per year with risk factorsAnnual CVA risk 23.5% for those aged 80 to 89 years

Copyright ©2005 American Heart Association

Verma, A. et al. Circulation 2005;112:1214-1222

Kaplan-Meier curves describing survival in 46 984 post-coronary bypass surgery patients at the

Cleveland Clinic from 1972 to 2000

AF and CVA Risk Factors• CHADS2

– Hypertension- even a history thereof =1– Diabetes =1– Congestive heart failure =1– Age >75 years– Prior TIA/CVA = 2

• Others– Prior MI– Echo data- LV dysfunction (EF<35-40%) , Left atrial

enlargement– Some argue age >60 or 65

BF Gage et al. JAMA 2001 285: 2864-2870.Krahn AD et al. Am J Med. 1995;98:476-84 .Atrial Fibrillations Investigators. Arch Intern Med. 1998;158:1316-20.

Risk for CVA: CHADS2

Score CVA risk/Yr

0 1.9%

1 2.8%

2 4.0%

3 5.9%

4 8.5%

5 12.5%

6 18.2%BF Gage et al. JAMA 2001 285: 2864-2870.

AF and Cardiomyopathy

• Rawles (Br Heart J 1990;63:157-61)-↓C.O. with HR>90• Tachycardia-induced Cardiomyopathy- may

occur with heart rates ≥ 105-110 BPM over 10-14 days– Reversible with proper rate control– Symptoms vary between patients

• Rate Control– AFFIRM

• Resting HR ≤ 80 BPM• 24 Hour Holter- Avg HR ≤ 100 BPM and no HR > 110% MTHR• HR ≤ 110 BPM during 6 minute walk test

Shinbane et al. J Am Coll Cardiol 1997;29:709-15.NHLBI AFFIRM investigators Am J. Cardiol 1997;79:1198-1202

AF in CHF: Prognostic Implications

V-HeFT no effect of AF

on mortality

Middlekauf Carson Dries Mahoney Crijns Mathew0

10

20

30

40

50

60

p=NSp=NS

Mo

rta

lity

(p

erc

en

t) Sinus Rhythm AF

…but SOLVD found RR 1.34, p=0.002 (Cox) Framingham HR for death 1.6 in males; 2.7 females (Cox)

V HeFT found no effect of AF on survival

Prevalence of AF and CHF

• 80% in “dropsy”– Mackenzie J. The

Oxford medicine,

1920:387-492.

• Clinical Trial data 15-30% AF, higher with worse NYHA

– Ehrlich, Nattel, and Hohnloser, JCE 2002 13: 399-405

AF and CHF- in sum• AF and CHF appear to co-promote • While treatment of LV dysfunction

prevents AF, converse not clear (except in poorly rate-controlled subjects)

• Clinical trial data highly desirable– AF-CHF – Randomized study of non-pharmacologic treatment in

subjects with LV dysfunction

Circulation. 2008;118:S_827

Prevention of CHF by treatment of AF

• Ablate and pace– Uncontrolled studies show improvements in

LV function– Controlled study- improved dyspnea and

exercise tolerance but not LV function • Circulation 1998;98:953-960• Mayo experience- does not alter prognosis

– NEJM 344:1043-1051

• Bi-V might be better– Eur Heart Journal 2002 23: 1780-1787

Can We fix it?

• Management Strategies– Rate Control

• Pharmacologic• Non-Pharmacologic

– Rhythm Control• Anti-arrhythmics• Surgical ‘correction’• Percutaneous ‘correction’

– Prevention

Rate vs. Rhythm

Fuster et al. JACC.2006;48(4):e149-246

-No significant difference in mortality-Anticogulation is essential regardless of strategy

Fuster, V. et al. Circulation 2001;104:2118-2150

Pharmacological management of patients with newly discovered AF

Assess for underlying disease:EchocardiogramIschemic Heart diesaseEndocrine diseaseOSA

CVA Risk Stratify

Rate Control Strategy

• AV nodal blocking Agents– Beta-receptor antagonists– Non-dihydropyridine Calcium channel

blockers– Digoxin-indirect via vagal effects

• Ablate and Pace

Rate control strategery

Farshi et al. JACC 1999; 33(2): 304-310

Dig-βb

Mayo Ablate and pace experience

NEJM 344:1043-1051

Rhythm Control Simplified

Fuster et al. JACC.2006;48:854-906

Fuster, V. et al. Circulation 2001;104:2118-2150

Arrhythmia-free survival after electrical cardioversion in patients with persistent atrial

fibrillation

DCC- >87% successful in most patientsOnly 25-35% of patients will be in sinus rhythm at one year

Kastor, J.A. Arrhythmias, Second Edition W.B. Saunders Co.. 2000: pp79-81

Anti-arrhythmics

Fuster et al. JACC.2006;48(4):e149-246

Dronedarone

-Contraindicated in Class IV CHF

Roy, D. et al. N Engl J Med 2000;342:913-920

Percentage of Patients Remaining Free of Recurrence of Atrial Fibrillation

18% of the patients receiving amiodarone and 11% of patients receiving sotalol or propafenone had to discontinue therapy because of adverse effects

RACE II

Surgical Modification

• Cox-Maze• Several

Modifications• Variable results

– ? Data

• Still considered the ‘Gold Standard’

Dr. Cox?

Evolution of percutaneous AF ablation

• 1994 John Swartz first reports endocardial maze procedure

• 1998 Haissaguerre isolates pulmonary vein “culprit”

• 1999-2003 more PVs, more foci

• 2003 Pappone anatomic approach

• 2004 Morady Need to isolate 4/4 veins

• 2004 Pappone ablate vagal efferent

Marine, Prog Card Disease 2005

Pulmonary Vein Isolation

Alternative approach

Success rates for ablation outside the PV

“success rates 2-3 times that of antiarrhythmic medications” Verma Circ 2005

Complication in Modern Series

JACC 2009;53:1798-803

-45 K procedures, 32.5 K patients, 162 centers-Between 1995 and 2006-0.98 in 1000 mortality

Cost in Medicare Dollars

-50% unsuccessful

Theory: Prevention

Paroxysmal AF

Persistent AF

yearsHypertensionSleep apnea

RAAS activationFibrosisDiastolic Dysfunction

Altered substrate

Altered electrophysiology

Permanent AF

Non-Antiarrhythmic Agents for Afib prevention

Summary

• Highly prevalent condition with significant associated morbidity and mortality– Driven mostly by thromboembolic events

• Decision to pursue rhythm control based on patient symptoms

• Rhythm control– Anti-arrhythmics still 1st line– Ablative or surgical therapy- case by case